Low gravity carbureted water gas



March 26, 1935.

J. A. PERRY ET AL LOW GRAVITY CARBURETED WATER GAS Filed Sept. 10, 1930 Jase 0 n L .f/all ITZIf/YE Patented Mar. 26, 1935 PATENT- OFFICE LOW GRAVITY CARBURETED WATER GAS Joseph A. Perry, Swarthmore, and Edwin L. Hall, Philadelphia, Pa., assignors to The United Gas Improvement Company, Philadelphia, Pa., a corporation of Pennsylvania Application September 10, 1930, Serial No. 480,930

Claims.

The present invention relatesto the manufacture of carbureted water gas.

The object of the invention is the provision of a novel method of (and apparatus for) the manu- 5 facture of carbureted water gas of low specific gravity.

In the distribution of combustible gas for domestic and industrial utilization, in many localities, coke oven gas or coal gas from retorts is used for the base load. The seasonal peaks due to the development of the house heating and other loads necessitate the production of large quantities of peak load gas. carbureted water gas is usually produced for these peak load demands. In such case the difference in specific gravity between coal or coke oven gas and carbureted water gas becomes an important factor. Carbureted water gas as ordinarily made has a considerably higher specific gravity than coal or coke oven gas of the same calorific power. For instance carbureted water gas of 530 B. t. u. per cu. ft. as ordinarily manufactured has a specific gravity in the neighborhood of 0.65 while coal gas or coke oven gas of the relatively same calorific power has a specific gravity in the neighborhood of 0.40.

With a base load of coke oven or coal gas, carbureted water gas as ordinarily made cannot be supplied direct to isolated customers but must be mixed with the coal or coke oven'gas at the plant. The amount of carbureted water gas which can be so produced and mixed is limited by the attendant increase in specific gravity of the mixed gas. The specific gravity of the mixed gas must be kept within certain limits so that satisfactory burner performance may be obtained from consumers appliances.

The present invention provides a simple and economical method of producing carbureted water gas of low specific gravity which can be mixed in large proportions with the base gas and still obtain satisfactory appliance burner performance.

It has been proposedto make a low gravity carbureted water gas in the ordinary water gas apparatus by blasting the generator fuel bed, burning the blast gases in the carbureter and superheater and storing their heat as ordinarily, making an uprun of steam through the fuel bed, and carbureting the resultant blue water gas by introducing oil to the carbureter during the passage of the blue gas through it, making a down run through the fuel bed by introducing steam and oil simultaneously to the superheater, vaporizing the oil and converting it to oil gas in the superheater and carbureter. In passage through the fuel bed the oil gas is partially decomposed releasing hydrogen and carbon, pro ducing a fixed gas composed of hydrogen and hydrocarbons which carburets the simultaneously produced blue water gas made by the reaction of the steam with the fuel and with released carbon. The resultant down run gas is a carbureted water gas of low specific gravity which when I.

mixed with the uprun carburetedwater gas of ordinary specific gravity, produces a gas of appreciably lower specific gravity than is ordinarily produced. I

The total oil required for enrichment and for partial decomposition is greater than the oil required to make carbureted water gas of ordinary specific gravity and the same calorific power. Therefore more heat must be stored in the carbureter and superheater for the vaporization of the increased quantity of oil and the fixing of oil gas than is necessary in the usual carbureted water gas process.

The storing of sufficient heat for this purpose in the carbureter and superheater, by the usual air blasting of the fuel bed produces temperatures in the fuel bed which are excessive forthe proper partial decomposition of the oil gas. These temperatures cause overcracking, and cause carbon to be liberated in such quantity and in such manner that considerable quantities escape as lampblack with the gas, which form emulsions with the tar produced that are very diflicult to handle. These temperatures also cause the production of hard pitch in quantities which are liable to block up the piping.

We have found that by air blasting the base of the fuel bed, and admitting secondary air to the upper portion of the generator so as to consume the producer gas generated by the primary blast, wholly or partially in contact with fuel in the upper part of the fuel bed and by leading the blast gases through the carbureter and superheater, completing their combustion there with further secondary air if necessary, the desired quantity of heat may be storedin the top of the fuel bed, the carbureter and super-- heater for the vaporization -of the increased quantity of oil and the fixing of the oil gas, that this heat is stored in a' manner making available an increased area of hot surface for oil vaporization. and fixing, and at the same time the blasting operation maybe carried on without producing in the fuel bed temperatures which are execessive in the partial decomposition of the oil gas passed therethrough.

.stored heat is utilized to vaporize oil and produce oil gas which is passed through the fuel bed with the steam and is partially decomposed, liberating carbon and hydrogen and producing a gas composed of hydrogen andhydrocarbons, which carburets the water gas simultaneously prov duced by the reaction of the steam with the fuel and with liberated carbon, thereby producing a carbureted' water gas of low specific gravity, which, when mixed with the uprun gas, produces a carbureted water gas of appreciably lower 'bed during the air blast, by admitting secondary air marginally to the upper portion of the fuel bed, producing an incandescent or relatively hot zone of ring form in the top of thefuel bed.

"The secondary air may, however, be introduced above the fuel bed.

We also prefer to follow the blasting operation by an uprun of steam admitted to the base of the fuel bed, conducting the resultant water gas through the carbureter and superheater, and during the rim carbureting it with oil admitted to the carbureter.

Following the uprun we prefer to make a down run with steam admitted to the superheatenandduring this run admit oil simultaneously to the top of the generator, spraying it onto the marginal hot zone at the top of the fuel bed. The oil is vaporized and partially decomposed by the stored heat and passes with steam through the fuel bed and is thereby further partially decomposed liberating carbon and hydrogen and with the simultaneously produced blue water gas, providing carbureted water gas of low specific gravity. Following the down run a short uprun is made to purge the set and the cycle isrepeated.

Operating aspreferred, a carbureted water gas of 530 B. t. u. and a specific gravity of .54 can be made using 11 lbs. of coke as generator fuel and 5 gals. of a typical gas oil per 1,000 cu. ft. of carbureted water gas, without difiiculties due to tar and lampblack emulsions and heavy pitch deposits.

The invention will be further described in connection with the attached drawing which shows partly in elevation and partly in vertical cross section, a carbureted water gas'set modified for the carrying out of our invention.

Referring to the drawing,

1 is the'generator, 2 the carbureter, 3 the superheater and 4 the washbox.

The generator 1 is provided with the fuel bed 5 which may be of coke or other solid fuel. The

generator is further provided with primary air blast supply means 6, leading into the base of the generator and the secondary air blast supply means 7, leading through the bustle pipe 8 and ducts 9 into the upper portion of the fuel bed, below the take-off, 10 leading to the carbureter.

The generator is further provided with the steam supply means 11" for upsteaming and with the oil supply means 12 provided with oil spray means 13. I

The carbureter 4 is provided with checkerbrick indicated as 14 and with the oil supply means 15. The carbureter is connected by connection 16 (showndotted) tothesuperheater 3, which is provided with the stack valve 17, the steam supply means 18 for downsteaming the fuel bed, the checkerbrick 19, and the gas oiltake 20, leading through the reversing valve 21 to the washbox 4.

The, generator is provided with a gas ofitake 22 for down-run gas also leading through the reversing valve 21 to the washbox. 23 is the offtake from the washbox to storage or other disposal.

In operationthe generator fuel bed is blasted with primary air supplied through 6, and the resultant producer gas burned with secondaryair marginally introduced through 7, the bustle pipe 8 and the ducts 9, therebyproviding'in addition to the usual hot zone produced bythe primary blast, an additional hot zone'of ring form in the top of the fuel bed. The resultant blast products pass through offtake 10, the carbureter 2, connection 16 and the superheater 3 and out of the set through stack valve 17, storing'their' heat in the carbureter and superheater.

When the required quantity of heat has been stored in the fuel bed and the carbureting vessels the air blast is shut off and the stack valve closed.

An uprun is made by introducing steam through 11. The resultant water gas is passed through the carbureter 2, superheater 3, and reversing valve 21 to the washbox A and thence to storage through ofl'take 23. 1

During the uprun, oil is introduced into th carbureter through oil supply means 15,- vaporized and the vapors'converted to fixed oil gas, thereby carbureting the uprun water gas.

At-the end of the uprun valve 21 is reversed and a down run is made by introducing steam to the superheater through steam supply means 18, passing it through the superheater and carbureter, where it is superheated and down through the fuel bed. During the down run, oil is introduced to the generator through oil supply means 12 and is delivered by spray 13 onto the previously heated marginal zone at the top of the fuel bed. The oil is vaporized by the heat stored in this zone as well as by radiant heat from the lining of the generator above the fuel bed, and partially cracked, to oil gas. The oil vapors and oil gas pass down through the fuel bed with the steam, and are partially decomposed, liberating'hydrogen and carbon producing a gas comprised of hydrogen and hydrocarbons and carbureting the blue water gas simultaneously produced by the reaction of the steam with the fuel bed and liberated carbon. The resultant carbureted water gas of low specific gravity is passed throughconnection 22, valve 21, washbox 4 and ofitake 23 to storage where it is mixed with the uprun gas.

During the down run we prefer to terminatethe oil admission before the end of the run, and for the latter part of the run to pass superheated steam alone down through the fuel bed, to dry up and thoroughly coke the oil residues on the top of the fuel bed, to prevent the combustion of 'volatile matter during the next blasting operathe carburetor, superheater and washbox to storage.

After this uprun the cycle may be repeated. A cycle of operations we have found successful may be given as an example.

Cycle Minutes.

Per cent Air blast 30 Uprunsteam to generator Uprun-steam to generator and oil to carbureter 14 Uprun-steam to generator 6 and superheater, which'process includes the fol-' lowing steps which are practiced in succession with heat stored by the air blast: air blasting the fuel bed and simultaneously burning the-blast gases so produced with secondary air introduced adjacent the upper marginal edge of the fuel bed; making an uprun with steam through the generator; making an uprun with steam through the generator and carbureting the resulting blue water gas with a hydrocarbon in the carburetor; making an uprun with steam through the generator; introducing steam to the superheater, passing the resulting gas down through the generator and simultaneously introducing a hydrocarbon onto the fuel bed adjacent theupper marginal-edge thereof; making a down run with steam through the generator; and making an uprun with steam through the generator.

2. An improvement in the process of manufacturing carbureted water gas in a set including a generator adapted to contain a fuel bed and a carbureting vessel, which process includes the following steps: one step being, air blasting the fuel bed and simultaneously burning with secondary airthe blast gases so produced in contact with the upper portion of the fuel bed and leading the burning blast gasesand the products oftheir combustion into and through said carbureting vessel; and another step being, making' a run with steam through the vessel and down through the generator while they still retain heat from the air blasting step therein and simultaneously introducing liquid hydrocarbon onto the fuel bed adjacent its upper marginal edge, thereby vaporizing the hydrocarbon with heat stored in the fuel bed, and passing the resulting hydrocarbon vapors and hydrocarbon gas down through the fuel bed together with the down-run steam, thereby cracking hydrocarbon vapors and hydrocarbon gas and generating water gas;

3. An improvement in the process of manufacturing carbureted water gas in a set including a generator adapted to contain an ignited fuel bed, which process includes the following steps: one step being, air blasting the fuel bed and simultaneously burning with secondary air the blast gases so produced in contact with the upper portion of the fuel bed; and another step being,

making a run with steam down through the incandescent fuel bed in the generator and simultaneously introducing heavy oil onto the fuel bed adjacent its upper marginal edge thereby vaporizing the heavy oil with heat stored in the fuel bed, and passing the resulting oil vapors and oil gas down through the fuel bed together with the down-run steam, thereby cracking oil vapors and oil gas and generating water gas.

4. A process of manufacturing carbureted water gas in a set including a generator, adapted to contain an ignited fuel bed, and a carbureting vessel, which process includes the followingsteps: one step being, air blasting the fuel bed and simultaneously burning blast gases so produced with secondary air in contact with the upper portion of the fuel bed and leading the burning blast gases and the products of their combustion through said carbureting vessel and storing heat therein; another step being, making an up-run with steam. through the incandescent fuel bed, simultaneously introducing heavy oil onto the top =of the fuel bed adjacent the marginal edge, thereby vaporizing said heavy oil with heat stored in the upper portion of the fuel bed by said combustion with secondary air, and simultaneously carbureting the blue water gas produced by said run with said vaporized heavy oil in the top of said generator and in said carbureting vessel; and another step being, making a down-run with steam through the ignited fuel bed, simultaneously introducing heavy oil onto the top of the fuel bed adjacent the marginal edge thereof, and passing the resulting oil vapor and oil gas down through the fuel bed together with the down-run steam, thereby cracking oil gas and oil vapor.

5. A process of manufacturing carbureted wa ter gas in a set including a generator adapted to contain a fuel bed and a carbureting vessel, which process includes the following steps: one step being, air blasting the fuel bed and simultaneously burning the blast gases so produced with secondary air in contact with the upper portion of the fuel bed and leading the blast gas through said vessel and storing heat therein; another step' being, making a run with steam through the fuel bed While it still retains heat therein from the air blasting step, spraying heavy oil on the top of the fuel bed, vaporizing said heavy oil with heat stored in the upper portion of the fuel bed by said combustion with second ary air, and simultaneously carbureting the blue water gas produced by said run with said vaporized heavy oil; and another step being, introducing liquid hydrocarbon to the fuel bed adjacent the upper marginal edge thereof, vaporizing the hydrocarbon by heat stored in the upper part of the fuel bed by said air blasting step,-passing steam and hydrocarbon vapor and hydrocarbon gas resulting from said vaporization down through the fuel bed while it still retains therein heat from the air blasting step, thereby generating blue water gas and cracking hydrocarbon in the fuel bed.

JOSEPH A. PERRY. EDWIN'L. HALL. 

